public int Threshold {get; set;}

{
  //Export each page of a map series to an individual TIFF file.
  string filePath = @"Path and file name for the output export file";
  //Create TIFF format with appropriate settings
  TIFFFormat TIFF = new TIFFFormat()
  {
    OutputFileName = filePath,
    Resolution = 300,
    ColorMode = TIFFColorMode.TwentyFourBitTrueColor,
    HasGeoTiffTags = true,
    HasWorldFile = true,
    ImageCompression = TIFFImageCompression.LZW
  };

  //Set up map series export options
  MapSeriesExportOptions MSExportOptions_TIFF = new MapSeriesExportOptions()
  {
    ExportPages = ExportPages.All,  //All pages
    ExportFileOptions = ExportFileOptions.ExportMultipleNames,  //Export each page to an individual file using page name as a suffix.
    ShowSelectedSymbology = true  //Include selection symbology in the output
  };

  //Export on the worker thread
  //Note: Must be on the QueuedTask.Run()

  //Check to see if the path is valid and export
  if (TIFF.ValidateOutputFilePath())
  {
    layout.Export(TIFF, MSExportOptions_TIFF);  //Export to TIFF
  }
}